Yesterday, Hollywood actor Michael Douglas announced that his battle with thyroid cancer was caused by oral sex – or more specifically, the HPV virus frequently contracted through oral sex.

The 68 year-old, who fought a six month battle with the disease from August 2010 until January 2011, initially blamed an indulgent lifestyle of cigarettes and alcohol.

But, in a rare example of modern male candour, the veteran performer revealed that his cancer was actually caused by the Human Papilloma Virus – a symptom-free bacteria that lives in the lining of the body’s cavities and can be passed on through sex or even the briefest physical touch.